dates one girl after the other! asap

What do you think of a guy thats dates and is in a relationship all the time?. I have a guy friend who can never stay single not even for a minute and constantly looking for next gf right away. He doesnt give himself space to be single and think of other things in life. Im sure his ex gfs think he never loved them if he moves on extremely fast. Hes been in a relationship with atlest 10 girls in the last 2 yrs. He also talks to me alot and flirts. I use to have a big crush on him few years ago and when i told him he would reject me many times but led me on to believe he likes me. I think he might try to date me in the future when he doesnt have girls anymore. Well im not going to be anyones 2nd option. I dont think hes a narc. His parents have been together very long time and theres no abuse or swearing of women. I just havent seen many guys i know who is so obsessed switching women. He bought his gf now 5 bouqets of pink roses. Hangs with her everyday. He even would search online dating for girls before.

I do not trust many guys now and i feel so insecure & afraid ill get hurt again.